1. Field of the Invention
This invention relates to elongated contact pad structures.
2. Description of the Related Art
Substrates with different coefficient of thermal expansion compared to silicon are used in three dimensional (3D) and 2.5D integrated circuits (collectively, 3DICs). Due to the difference in coefficient of thermal expansion, the substrates of the 3DICs may misalign. Furthermore, large monolithic dies with small contact bumps may also misalign from the contact pads of a substrate the monolithic die is connected to due to a mismatch om the coefficient of thermal expansion between the monolithic die and the substrate.
Thus, there is a need for an improved contact pad structure that stays aligned at room temperature, as well as at elevated temperatures.